The development and clinical evaluation of a tendon actuator is proposed that will match the force and motion characteristics of muscles responsible for controlling foot motion. The tendon actuator will attach to a cadaver foot tendon and will allow biomechanics researchers to manipulate the foot. Ultimately, a tendon actuator system, consisting of an array of eight tendon actuators, will enable the foot to be controlled in all degrees of freedom, in order to understand the etiology of a wide range of foot pathologies. In addition, the tendon actuator will be designed to integrate with the musculoskeletal simulator at the Cleveland Clinic Foundation (CCF), making it possible for the simulator to precisely mimic both gait kinematics and the stress distribution present on the underside of the foot. Eventually this system will be adapted to investigate human kinematics and pathologies in additional anatomic regions such as the wrist, shoulder, spine and knee. Initially, the program will focus on development of an Achilles tendon actuator capable of precisely tracking a prescribed demanding force profile accompanied by potentially demanding velocity, acceleration, travel and bandwidth requirements. After completion and test of a tendon actuator prototype at Foster-Miller, it will be attached to a cadaver and tested at the Biomechanics laboratory at CCF. The cadaver foot will be manipulated by attaching the Achilles tendon to the tendon actuator and mounting the tibia and fibula of the foot to an MTS system force actuator. A follow-on Phase II will include integration of a foot tendon actuator system (consisting of a full array of eight tendon actuators) with a cadaver foot and the musculoskeletal simulator to allow control of the cadaver foot in all degrees of freedom.